* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
  box-sizing: border-box;
  font-size: 12px;
  font-family: Roboto, San Francisco, Helvetica Neue, Helvetica, Arial, PingFangSC-Light, Hiragina Sans GB, WenQuanYi Micro Hei, microsoft yahei ui, microsoft yahei, sans-serif;
}